================================================================== BUG: KASAN: use-after-free in skb_loop_sk net/core/dev.c:1882 [inline] BUG: KASAN: use-after-free in dev_queue_xmit_nit+0xa0c/0xae0 net/core/dev.c:1911 Read of size 8 at addr ffff8801ca710ae0 by task sshd/2978 CPU: 0 PID: 2978 Comm: sshd Not tainted 4.13.0+ #43 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:52 dccp_close: ABORT with 528 bytes unread dccp_close: ABORT with 528 bytes unread print_address_description+0x73/0x250 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x24e/0x340 mm/kasan/report.c:409 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 skb_loop_sk net/core/dev.c:1882 [inline] dev_queue_xmit_nit+0xa0c/0xae0 net/core/dev.c:1911 xmit_one net/core/dev.c:2971 [inline] dev_hard_start_xmit+0x16b/0xac0 net/core/dev.c:2991 sch_direct_xmit+0x31d/0x6d0 net/sched/sch_generic.c:186 __dev_xmit_skb net/core/dev.c:3173 [inline] __dev_queue_xmit+0x15fe/0x1e40 net/core/dev.c:3440 dev_queue_xmit+0x17/0x20 net/core/dev.c:3505 neigh_hh_output include/net/neighbour.h:471 [inline] neigh_output include/net/neighbour.h:479 [inline] ip_finish_output2+0xece/0x1460 net/ipv4/ip_output.c:229 ip_finish_output+0x85e/0xd10 net/ipv4/ip_output.c:317 NF_HOOK_COND include/linux/netfilter.h:238 [inline] ip_output+0x1cc/0x860 net/ipv4/ip_output.c:405 dst_output include/net/dst.h:472 [inline] ip_local_out+0x95/0x160 net/ipv4/ip_output.c:124 ip_queue_xmit+0x8c6/0x18e0 net/ipv4/ip_output.c:504 tcp_transmit_skb+0x1947/0x3300 net/ipv4/tcp_output.c:1123 tcp_write_xmit+0x5fc/0x4960 net/ipv4/tcp_output.c:2341 __tcp_push_pending_frames+0xa0/0x250 net/ipv4/tcp_output.c:2516 tcp_push+0x4e0/0x760 net/ipv4/tcp.c:715 tcp_sendmsg_locked+0x17ad/0x3bc0 net/ipv4/tcp.c:1408 tcp_sendmsg+0x2f/0x50 net/ipv4/tcp.c:1445 inet_sendmsg+0x11f/0x5e0 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:633 [inline] sock_sendmsg+0xca/0x110 net/socket.c:643 sock_write_iter+0x320/0x5e0 net/socket.c:912 call_write_iter include/linux/fs.h:1743 [inline] new_sync_write fs/read_write.c:457 [inline] __vfs_write+0x68a/0x970 fs/read_write.c:470 vfs_write+0x18f/0x510 fs/read_write.c:518 SYSC_write fs/read_write.c:565 [inline] SyS_write+0xef/0x220 fs/read_write.c:557 entry_SYSCALL_64_fastpath+0x1f/0xbe RIP: 0033:0x7ff43cbff370 RSP: 002b:00007ffeac20aee8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000004028 RCX: 00007ff43cbff370 RDX: 0000000000004028 RSI: 000055dd1cb6f210 RDI: 0000000000000003 RBP: 0000000000000082 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 00000000009a0c9b R13: 00000000009a0000 R14: 00007ff43dcbac00 R15: 000055dd1cb59e30 Allocated by task 13791: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3627 kmalloc include/linux/slab.h:493 [inline] kzalloc include/linux/slab.h:666 [inline] fanout_add+0xa50/0x1190 net/packet/af_packet.c:1733 packet_setsockopt+0xfdc/0x1e80 net/packet/af_packet.c:3795 SYSC_setsockopt net/socket.c:1852 [inline] SyS_setsockopt+0x189/0x360 net/socket.c:1831 entry_SYSCALL_64_fastpath+0x1f/0xbe Freed by task 13801: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3503 [inline] kfree+0xca/0x250 mm/slab.c:3820 packet_release+0xa8f/0xd70 net/packet/af_packet.c:3033 sock_release+0x8d/0x1e0 net/socket.c:597 sock_close+0x16/0x20 net/socket.c:1126 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:246 task_work_run+0x199/0x270 kernel/task_work.c:112 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0xa52/0x1b40 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 get_signal+0x7e8/0x17e0 kernel/signal.c:2334 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:808 exit_to_usermode_loop+0x224/0x300 arch/x86/entry/common.c:158 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath+0x42f/0x500 arch/x86/entry/common.c:266 entry_SYSCALL_64_fastpath+0xbc/0xbe The buggy address belongs to the object at ffff8801ca710240 which belongs to the cache kmalloc-4096 of size 4096 The buggy address is located 2208 bytes inside of 4096-byte region [ffff8801ca710240, ffff8801ca711240) The buggy address belongs to the page: page:ffffea000729c400 count:1 mapcount:0 mapping:ffff8801ca710240 index:0x0 compound_mapcount: 0 flags: 0x200000000008100(slab|head) raw: 0200000000008100 ffff8801ca710240 0000000000000000 0000000100000001 raw: ffffea000765d520 ffffea0007630620 ffff8801dac00dc0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801ca710980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ca710a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801ca710a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801ca710b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801ca710b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================